"A Paladin's judgement is decisive, firm, sometimes painful, but always just."
Using Judgement is typically referred to as "Judging" a target. Judging a Seal a Paladin has cast on himself can result in a myriad of abilities, from damage to utility debuffs. If the Judgement is a debuff, the duration of it can be refreshed each time the Judging Paladin lands a melee hit.
The Retribution tier 1 talent Benediction reduces the cost of Judgement and Seals by 3%/6%/9%/12%/15%.
You can decrease the cooldown by 2 seconds of Judgement with Improved Judgement (2 ranks, 1 second per rank) in the Retribution Tree.
Sanctified Judgement (3 ranks) gives a 33%/66%/100% chance of receiving 50% of the mana back of the judged seal.
The Retribution tier 8 talent Fanaticism increases the critical strike chance of any Judgement that is capable of critical hits by 3%/6%/9%/12%/15%; this would include Righteousness, Command, Vengeance(?) and Blood.
The Tier 2 Paladin armor set is called Judgement Armor and includes an 8-piece set bonus that inflicts 60-66 additional Holy damage to the target a Paladin is Judging.
The set also offers a distinct and fitting look for Paladins and many Paladin-centric armor pieces in the Burning Crusade expansion have used variations of the Judgement set, normally a different color theme.